Lock-nut.



FILED JULY 23, 1903.

APPLIGA TION flit/6716071 ms NORRIS PErERs-cm, vmsnmcmn, n. c.

UNITED STATES PATENT OFFICE.

LOCK-NUT.

Specification of Letters Patent.

Patented March 12, 1907.

Application filed July 23,1903. Serial No. 166,750.

To all whom, it may concern.-

Be it known that I, ANDRE MINNE, a citizen of the French Republic,residing at Asnieres, France, have invented a certain new and usefulImproved Lock-Nut, of which the following is a specification.

This invention relates to a lock-nut shown, by way of example, in theaccompanying drawings.

Figure 1 shows an ordinary-nut and a locknut according to thisinvention. Fig. 2 is a plan view on the line C D of Fig. 1. Fig. 3 showsin elevation the device shown in Figs. 1 and 2.

In the constructions hitherto known the lock-nut has been always of thesame diam eter as the nut, and contact takes place along the wholesurface of their adjacent faces comprised in the interior of the circleinscribed in the hexagon. This construction has the following drawbacks:The effort in screwing the lock-nut being distributed over a largesurface, the useful effort for producing the locking effect isconsiderably reduced. It frequently happens in practice that there is nolocking action. In fact, in case of rough nuts, the faces not beingabsolutely normal to the axis of the bolt, the contact takes place at apoint on the outer circumference. In case of machined nuts it frequentlyhappens that the face presents a con cavity, so that the contact alsotakes place on the outer circumference. Under the circumstances theuseful effect of the lock-nut is practically m'l. Finally, the largecontact-surface and the gripping due to the tightening of the lock-nuton the nut cause the two nuts to adhere to each other and to formpractically a single nut, which becomes the more easily unscrewed, owingto its increased mass of weight.

The lock-nut according to this invention does away with the abovedrawbacks. The principles on which it is based are as follows:

First. Reduction to a minimum of the surfaces of contact of the two nutsby forming the two opposed faces or one of them-in the shape of atruncated cone of spherical or other surface, so that the small baseshall be a circle with a diameter equal to the outside diameter of thescrew-thread. The contact then takes place only on the small surface,which in Fig. 2 is shown crosshatchedthat is to say, on the right-handsection of the screw-thread. The advantage of this arrangement is thatit multiplies considerably the useful wedging effect at the point oftightening and absolutely prevents any unscrewing action. In case of atendency of the nut to unscrew the wedging will be even increased.

Second. Reduction to a minimum of the size and diameter of the lock-nutfor the purpose of preventing it from obtaining, under the action ofvibrations, a momentum capable of overcoming the wedging effort and ofbecoming unscrewed from the nut. Any vib'ration of both nuts willcommunicate in this construction a much greater momentum to the nut,thereby forcing it to engage all the more strongly with the lock nut. Itwill therefore no longer be necessary to use a cross pin or key, whichis'practically indispensable in the case of ordinary lock-nuts.

The cylindrical portion 1 of the lock-nut 2, Fig. 8, can be made withflats, or it may be milled, so as to enable a gas-spanner to be used.

In cases where vibration would be suflicient to lengthen the bolt andwhere, the nut becoming tightened, the lock-nut would be free to unscrewa second locknut could be used in front of the first. The two lock-nutswould maintain each other and produce, besides other advantages, theeflect of an ordinary lock-nut with pin.

The lock-nut may be made of steel or of any other metal.

The advantages are the same as those of an ordinary lock-nut.i. e.,facility of put ting in place, compensation of play, and cheapness,owing to its smaller weight an to the suppression of the pin.

What I claim as my invention, and desire to secure by Letters Patent, isI The lock-nut herein described having the contacting locking-facereduced to a crescent-shaped surface the greatest width of which isequal to the depth of the thread of the bolt.

In testimony whereof I have signed my name to this specification in thepresence of two subscribing witnesses.

ANDRE MINNE.

Witnesses:

JEAN ROBELET, Aucusrus E. INGRAM.

